This enormous section of the Milky Way galaxy is a mosaic of images from NASA's Wide-field Infrared Survey Explorer. The constellations Cassiopeia and Cepheus are featured in this 1,000-square-degree expanse. The colors used in this image represent specific wavelengths of infrared light. Blue and cyan (blue-green) represent light emitted at wavelengths of 3.4 and 4.6 microns, which is predominantly from stars. Green and red represent light from 12 and 22 microns, respectively, which is mostly emitted by dust. This image is a mosaic of thousands of individual frames from WISE, combined first into 442 interlocking tiles before re-projecting and stitching them into the final picture. This was done for each of the four WISE wavelengths, totaling nearly 30 billion pixels in the interlocking tiles. Credit: NASA/JPL-Caltech/UCLA